Update compile-fail/missing-do for new error-comment syntax

Author: brson

src/test/compile-fail/missing-do.rs

@@ -3,7 +3,7 @@
 fn foo(f: fn()) { f() }
 
 fn main() {
-    "" || 42; //! ERROR binary operation || cannot be applied to type `str`
-    foo || {}; //! ERROR binary operation || cannot be applied to type `extern fn(fn())`
-    //!^ NOTE did you forget the 'do' keyword for the call?
+    "" || 42; //~ ERROR binary operation || cannot be applied to type `str`
+    foo || {}; //~ ERROR binary operation || cannot be applied to type `extern fn(fn())`
+    //~^ NOTE did you forget the 'do' keyword for the call?
 }